Olympiad Class 8 Science Mock Test Set 04

Question. Which of the following statements is TRUE?
(A) A nylon thread is stronger than a steel wire
(B) Rayon is a natural fibre made from wood pulp
(C) Cotton is not a polymer
(D) Fabric made from polyester can get wrinkles easily
Answer : A

Question. Seema arranged two plane mirrors with different angles of inclinations of 30°, 45° and 60° respectively. She then observed the number of images being formed in each case. Which angle of inclination gives maximum number of images?
(A) 30°
(B) 60°
(C) 45°
(D) 90°
Answer : A

Question. Which of the following circuits gives the correct way of connecting an LED to light it up?

Answer : B

Question. Which instrument produces sound by vibrations of air column ?
(A) Veena
(B) Flute
(C) Mridangam
(D) Guitar
Answer : B

Question. Which part of the cell is wrongly matched with its function?
(A) Nucleus – controls the activities of the cell
(B) Cytoplasm – makes chlorophyll in green plants
(C) Cell wall – protects a plant cell
(D) Cell membrane – lets water and gas in and out of the cell
Answer : B

Question. Which of the following are examples of using streamlined shapes to reduce friction?
(A) Air craft
(B) Rocket
(C) Fish
(D) All of the above
Answer : D

Question. A burning candle when placed in a closed jar immediately gets extinguished as the supply of
(A) CO2 is cut off.
(B) O2 is cut off.
(C) N2 is cut off.
(D) Both (B) and (C)
Answer : B

Question. A polyethylene strip rubbed against a woollen cloth can attract small pieces of paper. What changes takes place on small pieces of paper during the application of the force ?
(A) The shape of the object
(B) The position of the object
(C) The density of the object
(D) The mass of the object
Answer : B

Question. Identify the odd one out.
(A) Chromosome
(B) Gamete
(C) Nucleus
(D) Gene
Answer : B

Question. CNG is preferred over petrol as a fuel for transport vehicles. Why?
(A) It is a renewable source of energy
(B) It is less polluting
(C) It can be compressed under high pressure
(D) It undergoes complete combustion
Answer : B

Question. It is easier to lift a stone inside water than out of it because of
(A) reflection
(B) refraction
(C) upthrust
(D) electrolysis
Answer : C

Question. For a given incident ray, the plane of the mirror makes an angle q with the incident ray then reflected ray is turned through 2q . This fact is used in which of the options given below?
(A) Periscope
(B) Kaleidoscope
(C) Shaving mirrors
(D) Automobile head lights
Answer : A

Question. Which of these organisms cause malaria?
(A) Entamoeba histolytica
(B) Salmonella typhi
(C) Trypanosoma
(D) Plasmodium
Answer : D

Question. Which kind of clothes dry faster in the rainy season?
(A) Cotton
(B) Wool
(C) Polyester
(D) Jute
Answer : C

Question. Arrange the following cell organelles in descending order based on their size.
P-Chloroplast, Q-Ribosome,
R-Nucleus, S-Lysosome
(A) Q,S,P,R
(B) Q,S,R,P
(C) R,P,S,Q
(D) R,P,Q,S
Answer : C

Question. Which of the following statements is NOT correct?
(A) All vegetables are good conductors of electricity
(B) The solution used for electroplating is a polluting waste
(C) Acids are bad conductors of electricity
(D) An electric bulb glows due to heating effect of current
Answer : C

Question. Which of the following does not belong to the group formed by the others?
(A) Poliomyelitis
(B) Mumps
(C) Rabies
(D) Typhoid
Answer : D

Question. When friction is useful?
(A) Sharpening a pencil
(B) Striking a matchstick to light it
(C) Walking on ice
(D) All of the above
Answer : D

Question. Which reaction does not give hydrogen as a product based on their reactivity?
(A) The adding of rubidium to water.
(B) The adding of tin to dilute hydrochloric acid.
(C) The electrolysis of aqueous gold chloride.
(D) The electrolysis of aqueous rubidium chloride.
Answer : C

Question. During lightning, streaks of bright light are seen. This is due to
(A) UV rays from the sun
(B) IR rays from the sun
(C) Discharge of accumulated electric charges
(D) Cosmic rays
Answer : C